提交 8cab77a2 编写于 作者: A Adrian Bunk 提交者: Sam Ravnborg

Kconfig: remove the CONFIG_CC_ALIGN_* options

I don't see any use case for the CONFIG_CC_ALIGN_* options:
- they are only available if EMBEDDED
- people using EMBEDDED will most likely also enable
  CC_OPTIMIZE_FOR_SIZE
- the default for -Os is to disable alignment

In case someone is doing performance comparisons and discovers that the
default settings gcc chooses aren't good, the only sane thing is to discuss
whether it makes sense to change this, not through offering options to change
this locally.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
上级 7d185983
......@@ -472,13 +472,6 @@ else
CFLAGS += -O2
endif
#Add align options if CONFIG_CC_* is not equal to 0
add-align = $(if $(filter-out 0,$($(1))),$(cc-option-align)$(2)=$($(1)))
CFLAGS += $(call add-align,CONFIG_CC_ALIGN_FUNCTIONS,-functions)
CFLAGS += $(call add-align,CONFIG_CC_ALIGN_LABELS,-labels)
CFLAGS += $(call add-align,CONFIG_CC_ALIGN_LOOPS,-loops)
CFLAGS += $(call add-align,CONFIG_CC_ALIGN_JUMPS,-jumps)
ifdef CONFIG_FRAME_POINTER
CFLAGS += -fno-omit-frame-pointer $(call cc-option,-fno-optimize-sibling-calls,)
else
......
......@@ -354,43 +354,6 @@ config SHMEM
option replaces shmem and tmpfs with the much simpler ramfs code,
which may be appropriate on small systems without swap.
config CC_ALIGN_FUNCTIONS
int "Function alignment" if EMBEDDED
default 0
help
Align the start of functions to the next power-of-two greater than n,
skipping up to n bytes. For instance, 32 aligns functions
to the next 32-byte boundary, but 24 would align to the next
32-byte boundary only if this can be done by skipping 23 bytes or less.
Zero means use compiler's default.
config CC_ALIGN_LABELS
int "Label alignment" if EMBEDDED
default 0
help
Align all branch targets to a power-of-two boundary, skipping
up to n bytes like ALIGN_FUNCTIONS. This option can easily
make code slower, because it must insert dummy operations for
when the branch target is reached in the usual flow of the code.
Zero means use compiler's default.
config CC_ALIGN_LOOPS
int "Loop alignment" if EMBEDDED
default 0
help
Align loops to a power-of-two boundary, skipping up to n bytes.
Zero means use compiler's default.
config CC_ALIGN_JUMPS
int "Jump alignment" if EMBEDDED
default 0
help
Align branch targets to a power-of-two boundary, for branch
targets where the targets can only be reached by jumping,
skipping up to n bytes like ALIGN_FUNCTIONS. In this case,
no dummy operations need be executed.
Zero means use compiler's default.
config SLAB
default y
bool "Use full SLAB allocator" if EMBEDDED
......
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